The short answer
No. Your data. Shrink it from its app; don’t delete the folder.
What is it?
A macOS software update that Software Update has downloaded and prepared, waiting to be installed, in a protected system folder. Minor updates are usually a few GB; major upgrades take much more.
An update macOS has prepared. It is removed once installed; MoreRoom cannot delete it.
What happens if you delete it?
macOS removes it once the update is installed. If it disappears beforehand, Software Update downloads it again.
How to remove it properly
Do not try to delete it by hand: the folder is protected by System Integrity Protection. To get the space back, install the update from System Settings › General › Software Update and restart; the prepared files are cleared afterwards.
Don’t remove it by hand; macOS manages it.
Before you delete it
To stop macOS downloading updates before you are ready, click the info button next to Automatic Updates in Software Update and turn off downloading new updates when available.
How MoreRoom helps
MoreRoom recognises this as your data and never suggests deleting it. It shows how much space it takes, so you can shrink it from its own app.
Frequently asked questions
Can I delete a downloaded macOS update?
No. Your data. Shrink it from its app; don’t delete the folder. macOS removes it once the update is installed. If it disappears beforehand, Software Update downloads it again.
Will Downloaded macOS update come back after I delete it?
Yes. macOS removes it once the update is installed. If it disappears beforehand, Software Update downloads it again.
How do I remove Downloaded macOS update properly?
Do not try to delete it by hand: the folder is protected by System Integrity Protection. To get the space back, install the update from System Settings › General › Software Update and restart; the prepared files are cleared afterwards.